Heart Care

Drug-Coated Stents Best for Some after Heart Attack

Drug-coated stents are more effective than the bare metal kind for people who have heart attacks, says a study reported in the New England Journal of Medicine.

The death rate, incidence of second heart attacks, and need for new artery-opening procedures were lower for those getting drug-coated stents. The study looked at 7,000 people treated for heart attacks in Massachusetts in 2003 and 2004.

"We were looking to see if there was a risk, and we actually saw there was a benefit," says study author Dr. Laura Mauri, at Harvard Medical School.

Stable Condition a Plus for Coated Stents

In the two years after stents were implanted in arteries reopened after a heart attack, 8.5 percent of the 4,016 recipients of drug-coated stents died, compared to 11.6 percent of the 3,201 recipients of bare-metal stents.

Second heart attacks struck 7.4 percent of coated stent recipients and 8.5 percent of those getting bare-metal stents. And new artery-opening procedures were required for 10.7 percent of the coated stent recipients, compared to 14.9 percent of those getting bare-metal stents.

The results are close to those reported recently by a group led by Dr. Peter W. Groeneveld, at the University of Pennsylvania, who analyzed Medicare data on 72,000 stent recipients.

"Our population was slightly different from theirs," says Dr. Groeneveld. "We used both patients who had heart attacks and didn't, but the relative difference in rates of death and heart attacks after the procedures seems to be what we found."

The new study "is very important, because it is a large study with long-term follow-up," says Dr. Mauri.

"The strength of this study is that these guys have more detailed clinical information on the patients than we did," notes Dr. Groeneveld. "The results are very similar. We think we are looking at the same thing."

There has been a general shift toward use of coated stents among patients having the artery-opening procedure called angioplasty, notes Dr. Groeneveld.

Coated stents were approved by the US Food and Drug Administration (FDA) in 2003, and the two approval studies were done "in a period of time when the cardiology community was transitioning over to drug-eluting stents, a process of adopting new technology," he says.

Overall, "about two-thirds to three quarters of patients now get drug-eluting stents," says Dr. Groeneveld.

But that change does not necessarily apply to cases where stents are implanted because of a heart attack, explains Dr. Mauri.

"Acute myocardial infarction [heart attack] is one setting where physicians are still concerned about safety, so we are still close to 50-50," she says. "[When] the patient is stable, the percentage of drug-eluting stents is much higher."

Some Cases are Better for Plain Stent

One important reason why a bare-metal stent is implanted after a heart attack is fear that the recipient might not follow advice to take the clot-preventing drug clopidogrel, says Dr. Mauri.

"If they can't take clopidogrel long-term, there may be a higher risk of thrombosis [blockage],” she says.

This risk is believed to be linked to a biologic response to drug-eluting stents in patients with a thrombotic occlusion.

And bare-metal stents can be appropriate for many people who require angioplasty, says Dr. Groeneveld.

"There are patients who benefit from bare-metal stents," he says. "Sometimes, they are the right choice because of the location of the blockage, the size of the blood vessel, and the potential complications that can occur with drug-eluting stents."

While drug-coated stents do better on average, that does not mean that every single individual should get a drug-eluting stent rather than a bare-metal stent.

December 2008

Heart Attack Defined

A heart attack, or myocardial infarction (MI), occurs when one or more regions of the heart muscle experience a severe or prolonged lack of oxygen caused by blocked blood flow to the heart muscle.

The blockage is often a result of atherosclerosis - a buildup of plaque, known as cholesterol, other fatty substances, and a blood clot. Plaque ruptures and eventually a blood clot forms.

The cause of a heart attack is a blood clot that forms within the plaque-obstructed area.

If the blood and oxygen supply is cut off severely or for a long period of time, muscle cells of the heart suffer damage and die.

The result is dysfunction of the muscle of the heart in the area affected by the lack of oxygen.

The following are the most common symptoms of a heart attack:

severe pressure, fullness, squeezing, pain, and/or discomfort in the center of the chest that lasts for more than a few minutes

pain or discomfort that spreads to the shoulders, neck, arms, or jaw

chest pain that increases in intensity

chest pain that is not relieved by rest or by taking nitroglycerin

chest pain that occurs with any/all of these symptoms including sweating, cool, clammy skin, and/or paleness; shortness of breath; nausea or vomiting; dizziness or fainting; unexplained weakness or fatigue; or rapid or irregular pulse

Although chest pain is the key warning sign of a heart attack, it may be confused with indigestion, pleurisy, pneumonia, or other disorders.

Always consult your physician for more information.

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